Topic: Steering head beariings

[pelicanwheel]

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[pelicanwheel]

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[HondaMan]

Great work, Pelican! Those are all the right numbers, spacers and all.

The KML 30-50H interests me: that's the right sizes, but the proportions of the outer race suggest the same problem I have: someone had to grind them, leaving a thinwall cup (not a problem, though, at these loads). The triple tree tube is 30mm at the bottom (ID) and the steering head is 50mm, more accurately 50.05mm, at the bottom. One can buy 50.05mm cups, but the matching bearing is 26mm ID, a lot of ID grinding. One can buy 30mm ID bearings, but they now only fit into 55mm cups - again, a lot of grinding. In the early 1970s I could buy these KML sizes, so someone is manufacturing them again.

But, I've been too busy with swingarm bushingss for SOHC-ers lately to finish the steering head bearing project. Someday....

[pelicanwheel]

Hondaman -

Unless they sent a lot of time polishing, the bottom cup doesn't appear to be altered from original manufacture.  In other words, it doesn't look like it was ground down to fit.  Now of course they could have simply taken the time to polish after grinding, but that's a lot of work.

The instructions says to measure the original stack height of the ball bearings.  It's too late for me now as I have aready distroyed the race on the lower stem.  I'm afraid to put the new rollers on without a spacer, then find out I need it , then screw up the rollers taking it off to put the spacer on.  How can I know for certain before hand?

Thanks,

Pelican

[HondaMan]

Hondaman -

Unless they sent a lot of time polishing, the bottom cup doesn't appear to be altered from original manufacture.  In other words, it doesn't look like it was ground down to fit.  Now of course they could have simply taken the time to polish after grinding, but that's a lot of work.

The instructions says to measure the original stack height of the ball bearings.  It's too late for me now as I have aready distroyed the race on the lower stem.  I'm afraid to put the new rollers on without a spacer, then find out I need it , then screw up the rollers taking it off to put the spacer on.  How can I know for certain before hand?

Thanks,

Pelican

Sorry to be so long in replying: I missed your post.   

The tightness you're experiencing is due to the post being 50.02mm outside dimension and the bearing 50.00 ID, an interference fit.

By now, I hope you've found out that the spacer should be installed. If the bearing is that tight going on, then emery-paper the steering stem and clean it with steel wool to make it slide a little better. Then grease everything (after a real good cleaning) and assemble. If you want to install/uninstall the bearing, use 2 flat screwdrivers on either side of the bearing and steering crown, tapping them in a little at a time on alternate sides until it comes loose. Usually, rust over the years has expanded the tube a little, plus the interference fit, which is not necessary, makes things harder.